In my startup, one of my partners has a small hosting company and deals with servers and infrastructure, but as a technical-but-not-full-time-sysadmin startup founder, Pingdom gives the easy, basic monitoring I just need to know if things are not going the right way.
1. We monitor many of their nodes not working for at least 5-10 mins/day which provides many false positives 2. The few time we needed tech support answers were slow and they did not provide proper answers/solutions to the issues we had (broken dashboards, missing checks etc)
I have used this kind of software for a long time and recently switched to Pingdom because it offers more reporting (such as load times over time). That is worth the slightly extra cost to me. Obviously, this kind of software is a must for any e-commerce site and it simply has to work. To date, it has worked fine.
We've used other services for availability monitoring, but Pingdom does that job and does it better. The pricing on the medium tiers seems a bit high and their UI can be a bit confusing at times. But hopefully, you aren't having to use it very often.
It make easy check the online status of any server, including, reading data from json endpoints. It's a must have.
My team and I thought pingdom is too expensive for what it can offer however we discover its capabilities and more usages after using for 6 months or so. Long term wise, it is better (in terms of cost) to use pingdom to monitor uptime, page speed etc. I have yet to reached its customer support so far, so i have decided to give it a 4-star.
What to know why your website is running slow? Try the site speed test on Pingdom. I regularly use this when troubleshooting client sites.
Pingdom was often a lifesaver for me. I would be notified before my web host even knew there was an issue and that allowed me to stay on top of website downtime. When you're managing several sites and they all go offline though ... The SMS notifications can get tiresome. Still, they keep you motivated.